不同旱害级别对开割和未开割橡胶树形态和生理特性的影响

Effects of Different Drought Grades on the Morphological and Physiological Characterizations of Tapping Tree and Virgin Tree of Hevea brasiliensis

干旱会导致巴西橡胶树生长迟缓、落叶和死皮率增加。本研究对比分析巴西橡胶树RRIM600不同旱害级别开割树和未开割树胶乳产量、形态、土壤含水量和叶片叶绿素含量等生理指标的变化规律。结果表明,随着旱害级别的升高,开割树胶乳干胶含量和总固形物维持在较高水平,不适于割胶。未开割树和开割树生理响应规律一致,均表现叶片面积呈现逐渐显著减小,叶片中的色素含量逐渐减少,但Chla/Chlb的值没有明显变化。叶片中PRO、SS、SOD和POD对干旱有保护作用的规律。说明干旱条件下橡胶树表现出的特性是叶面积减小,渗透调节物质含量和抗氧化物酶活性增加。本研究为建立橡胶树新干旱分级标准和筛选抗旱诊断指标奠定基础。

Drought will cause growth retardation, leaf falling and increase TPD rating in rubber tree（ Hevea brasiliensis）. In this study, different drought grades of RRIM600 tapping tree and virgin tree were used for comparison of the variations of latex, phenotypes, soil water contents, chlorophyll contents and other leaf physiological indices. The results showed that the DRC and TSC maintained at a high level in tapping tree, which not suitable for tapping with the increase of drought grades. Both tapping tree and virgin tree showed the same physiological responsive mechanism. Leaf area decreased gradually with the increase of drought grades. Chlorophyll contents reduced, but the Chla/Chlb ratio did not show obvious change in the leaves. Pro, SS, POD and SOD showed protection roles in drought stress. These results suggest that the leaf area would reduce, and the osmoregulation substance contents and antioxidant enzyme activities would increase under drought conditions. This study lay a good foundation for the establishment of a new rubber drought grades classification standards and screening drought diagnosis index in rubber tree.